For economic reasons electrolysis of dilute brines such as sea water or brackish water is not practicable. This is especially true for exhaustive electrolysis to produce deionized water.
In ordinary electrodialysis, on the contrary, brackish water of 2000 or 3000 parts per million of salt is economically desalinated; but sea water at 35,000 ppm of salt is more economically desalinated by, for example, one of the forms of distillation.
I have invented a novel form of electrodialysis whereby it is economical to desalinate sea water, since, in addition to deionized water, caustic soda, chlorine, and hydrogen are produced. The value of the caustic soda and chlorine produced is such as to more than defray the entire cost of my novel form of electrodialysis.
In contradistinction to all processes for desalination, costs for which are borne by the deionizd water produced, my new form of electrodialyis prmits economical production of deionized water not only for domestic and industrial use but for use in agriculture as well.